The present invention relates to an anchoring device for passive seat belts.
Nowadays it is compulsory for passenger automobiles to be fitted with seat belts; however, often passengers neglect to fasten the belts. Therefore, it is contemplated to make the fitting of so-called passive passenger restraint systems compulsory. One such system is a passive seat belt system in which the seat belts are automatically fitted onto the passengers as they sit in the automobile and are automatically locked on them.
In the majority of such passive seat belt systems, one anchoring point of the belts is above the vehicle door, on a slide rail just above the door edge, and the belt is attached to a slide member that moves along the rail in accordance with the opening and shutting of the door, so that the slide member moves forward when the door is opened, and backward when it is closed, so as to tighten the seat belt automatically on the passenger.
In such a structure, it is necessary to provide some sort of locking device to lock the slide member to the vehicle when the vehicle door is closed and the vehicle is being driven, in order to provide positive safety for the seat belt system. Heretofore, such locking has been done electrically, by a solenoid which is activated by the movement of the door, or by the operation of a drive motor which moves the slide member along the rail. Such a system, however, requires both electric components and mechanical components to perform the locking. Hence it is expensive and has reliability problems.